Development

The development is the middle section of a sonata-form movement. Its function is to develop — manipulate, fragment, recombine, modulate — the themes presented in the exposition. The development typically explores remote keys, breaks themes into fragments, sets fragments against each other in counterpoint, and builds toward the climactic moment of recapitulation.

The development is the most experimental and dramatic part of sonata form. While the exposition presents themes and the recapitulation reaffirms them, the development is where the music goes on a journey — through unexpected keys, through textural transformations, through dramatic confrontations. Beethoven’s developments are particularly famous for their length and intensity.

The close of the development — the moment of return to the home key for the recapitulation — is typically marked by a passage of harmonic tension building to a release. The skill of the composer is most evident in how the development unfolds and how it leads back to the recapitulation.

English, ‘unfolding’, from Old French desveloper (‘to unwrap, develop’).

Treat development passages as exploratory. Themes are fragmented and recombined; the music feels less stable than in the exposition. Embrace the harmonic instability; it is part of the form’s drama.